What is network denial of service (DoS), and why is it such a problem? This research project has sought to investigate these questions and look at the deeper questions such as can denial of service be removed, can it be detected and can network systems adequately respond to denial of service incidents should they become subjected to them? This paper describes some issues that make network denial of service a difficult security problem, and discusses some solutions that have been provided by the security research community. The paper then provides a classification of denial of service, the Consumer problem and the Producer problem, which forms the bulk of modern network denial of service incidents. Finally the paper proposes requirements for a framework for the management of response to network denial of service incidents, and suggests future directions that are being developed to create the framework.